Sources: 4th amendment / privacy issues

Ok, here's the kicker. I'm writing a mini-thesis (15-20 pages) on the current status of the Bush administration's effect on the 4th amendment for private citizens in the US for a class in American politics. Is there any chance someone here could recommend a few good sources to non-extremist articles on the issue? Internet-based preferable, but I don't mind buying a book or two if it's worth it. Like I said, I'm not looking for neither the Bush is Satan or Bush is a Saint extremist views, I really want sources that are somewhat balanced and reasonable (does this still exist?)